Preparation of high activity catalysts; the catalysts and their use

ABSTRACT

A process for the preparation of a catalyst useful for conducting carbon monoxide conversion reactions, especially a Fischer-Tropsch catalyst, use of the catalyst for conducting such reactions, especially Fischer-Tropsch reactions, and the composition produced by said process. In the preparation of the catalyst, a solution of a polyol is employed to impregnate and disperse a compound or salt of a catalytic metal, or metals, e.g., copper or an Iron Group metal such as iron, cobalt, or nickel, or in a preferred embodiment both a compound or salt of rhenium and a compound or salt of a catalytic metal, or metals, e.g., copper or an Iron Group metal such as iron, cobalt, or nickel onto a refractory inorganic oxide support, e.g., titania. The rhenium, when present only in small amount permits full and complete reduction of the catalytic metal, or metals, dispersed by the polyol. Higher catalyst activities with lower rhenium loadings are thus achieved than in previous preparations where higher concentrations of rhenium were required to both effectively disperse, and reduce the catalytic metal, or metals, during the preparation. Surprisingly, as little as about {fraction (1/10)} of the rhenium is required to accomplish the reduction promotion where the dispersion is effected with the polyol.

This is a division of application Ser. No. 08/845,015, filed Apr. 22,1997.

FIELD OF THE INVENTION

This invention relates to a process, or method, for the production of ahigh activity catalyst by dispersion of a catalytic metal, or metals,particularly copper or an Iron Group metal, notably cobalt, or both acatalytic metal and rhenium onto a refractory inorganic oxide support,notably titania; the catalyst; its reduction, and use of the catalystfor conducting carbon monoxide hydrogenation reactions, especiallyFischer-Tropsch reactions.

BACKGROUND

Carbon monoxide hydrogenation reactions are well known. For example,Fischer-Tropsch synthesis processes, or processes for the catalyticconversion of synthesis gas, i.e., a mixture of hydrogen and carbonmonoxide, to high quality distillate fuels or mixtures of C₅+ liquidhydrocarbons are well known. For example, the Group VIII non-noblemetals, iron, cobalt, and nickel have been widely used to catalyzeFischer-Tropsch reactions, and these metals have been deposited onvarious supports, and promoted with various other metals. In U.S. Pat.No. 4,568,663, e.g., there is disclosed a process of this type whichutilizes a highly active catalyst composition constituted ofcobalt-rhenium-titania, Co—Re—TiO₂. This catalyst is made, e.g., byimpregnating a concentrated aqueous solution of cobalt nitrate andperrhenic acid onto a titania support by the conventional incipientwetness method, drying, and then calcining to decompose the nitrate saltto the oxide. Several important functions are served by the rhenium. Amajor function is served by rhenium during the calcination of thecatalyst, during which cobalt nitrate decomposes to cobalt oxide, inthat it causes the cobalt oxide to become more highly dispersed. It alsopreserves the cobalt oxide in highly dispersed state under hightemperature oxidizing conditions, such as is found useful forregenerating cobalt catalysts. It is also a function of the rhenium tolower the temperature of the reduction of cobalt oxide to the zerovalence state, which is required to achieve full activity. Rhenium makesit easier to more fully reduce the cobalt. High dispersal, and fullreduction of the cobalt results in a more active catalyst. This resulthowever does not come without cost, for rhenium is a relativelyexpensive commodity. Thus, there exists a need for means to betterdisperse the cobalt with a lesser amount of rhenium, find means forrecovering the rhenium, or find other more available, less expensivematerials for promoting the dispersion, and reduction of the metals.

SUMMARY OF THE INVENTION

The present invention, which meets this and other needs, relates to anovel process for the preparation of a catalyst useful for thehydrogenation of carbon monoxide, especially to a Fischer-Tropschcatalyst, the catalyst, and process for the use of this catalyst forconducting such reactions, especially Fischer-Tropsch synthesisreactions, i.e., reactions for the production of C₅+ liquid hydrocarbonsfrom hydrogen and carbon monoxide. In the preparation of theFischer-Tropsch catalyst, a preformed particulate refractory inorganicsolids support is impregnated with (a) a compound, or salt, of acatalytic metal, or metals, suitably copper or an Iron Group metal and(b) a polyol or polyhydric alcohol. And preferably, a preformedparticulate refractory inorganic solids support, preferably titania, isimpregnated with (a) a compound, or salt, of a catalytic metal, ormetals, suitably copper or an Iron Group metal, (b) a polyol, orpolyhydric alcohol, and (c) a compound, or salt, of rhenium. Inimpregnating the support, the support is contacted, preferably, with asingle solution containing both (a) and (b), or all of (a), (b), and(c), respectively. The polyol is sufficient to distribute the compoundor salt of the catalytic metal, copper or Iron Group metal in highlydispersed form, onto the support; and, the rhenium, when added, issufficient to produce full reduction of the dispersed metal. Whereasrhenium has been used in the past to produce both of these functions, afar lesser amount of rhenium is required to produce both dispersion andreduction of the metal when the rhenium is used in conjunction with thepolyol.

Polyols useful in the practice of this invention are characterized asmolecules containing straight carbon chains, at least two carbon atomsof which bears a hydroxyl group; the preferred polyols having thefollowing empirical formula:

C_(n)H_(2n+2)O_(x)

where n is an integer ranging from 2 to about 6, and x is an integerranging from 2 to n. In other words, n is 2, 3, 4, 5 or about 6, and 2≦x≦ n this including such polyols as 2,3-dihydroxybutane,2,3,4-trihydroxypentane, 2,2-dihydroxyhexane, 2,2,4-trihydroxyhexane,and including more preferably the sugar alcohols; most preferably thosealcohols having the formula

HOCH₂—(CHOH)_(n′)—CH₂OH

where n′ is an integer defining the number of CHOH groups, or groups ina straight chain of carbon atoms each of which bears a hydrogen and ahydroxyl group, n′ ranging from 0 to about 4, and more preferably fromabout 2 to about 4. Exemplary of polyhydric alcohols, or polyols, usefulin the practice of this invention are glycol, a dihydric alcohol;glycerol, a trihydric alcohol; tetritols such as erythritol, threitol,and the like; pentitols, such as ribitol, arabinitol, xylitol, and thelike; and hexitols, such as allitol, dulcitol, gluciotol, sorbitol,mannitol, and the like.

It has been found that the copper or Iron Group metal can be moreeffectively dispersed onto the support via use of the polyol than withrhenium, as a consequence of which no rhenium is required to effect afull, and complete dispersion of the catalytic metal, or metals.However, some rhenium is generally useful, and sometimes required sinceits presence enables a more complete and full reduction of the dispersedcopper or Iron Group metal to the zero valent state. Accordingly, in thepreferred practice of this invention, a small amount of a compound orsalt of rhenium, and both a compound or salt of copper or an Iron Groupmetal and a polyol are employed to disperse the copper or Iron Groupmetal, and rhenium, into the solids support component of the catalystduring the impregnation; dispersion of the copper or Iron Group metalinto the preformed catalyst resulting from the presence of the polyol,while the rhenium is effective in permitting full reduction of thecatalyst after calcination. The copper or Iron Group metal compound, andrhenium compound, are thus effectively dispersed during the impregnationstep, and during calcination the polyol is removed by combustion leavingbehind crystallites of well dispersed oxides of the copper or Iron Groupmetal and the rhenium. Essentially complete reduction of thecrystal-lites of the metals is achieved on contact of the calcinedcatalyst with a reducing agent, e.g., hydrogen. Surprisingly, in thepreparation of a catalyst it is found that considerably less rhenium isrequired overall when prepared with a polyol to produce a full, similarlevel of activity in a reduced copper or Iron Group metal/rheniumcatalyst of given composition, used in a carbon monoxide hydrogenationor Fischer-Tropsch reaction, than with a reduced catalyst ofcorresponding composition, used in a similar carbon monoxidehydrogenation or Fischer-Tropsch reaction at similar process conditions,made in a preparation otherwise similar except that the catalyst wasmade without use of a polyol.

DETAILED DESCRIPTION

The catalysts are formed by deposition of the catalytic metal, ormetals, on a previously pilled, pelleted, beaded, extruded, spray dried,or sieved support material by the impregnation method. In preparing thecatalysts, the metals are deposited from solutio-n on the support inpreselected amounts to provide the desired absolute amounts, and weightratios of the metals being deposited. Catalysts constituted of cobaltand rhenium supported on titania, or a titania-containing support,silica, etc. with or without the addition of an additional metal, ormetals, promoter or modifier, e.g., ruthenium, hafnium, zirconium,titanium, chromium, thoria, copper, etc., exhibit superior hydrocarbonsynthesis characteristics and provide high selectivities in theconversion of synthesis gas to C₅+ hydrocarbon liquids. Suitably, themetals are codeposited by contact and treatment of the support with asolution, suitably an aqueous solution, which contains the polyol, e.g.,sorbitol, in addition to the compound or salt of the copper or IronGroup metal, e.g., cobalt, or the compound or salt of the rhenium, orboth the compound or salt of the copper or Iron Group metal and thecompound or salt of the rhenium.

The catalytic metal, copper or Iron Group metal, and the rhenium can bedeposited from solution in sequence, or codeposited from the sameimpregnating solution, and the polyol can be deposited from solution insequence with the copper or Iron Group metal, and rhenium, orcodeposited with the copper or Iron Group metal and the rhenium. Thepolyol can thus be codeposited with a catalytic metal, or metals, or itcan be deposited from solution by a separate impregnation. Preferablyhowever, the polyol is codeposited with the copper or Iron Group metaland the rhenium. The volume of impregnating solution used in animpregnation usually ranges from about 1 to about 20 times the volume ofthe support, and is generally carried out at ambient or elevatedtemperature. Preferably, the impregnation is carried out at conditionsof incipient wetness, and at essentially ambient temperature. Inaccordance with the incipient wetness technique, as is known, the volumeof the impregnating solution and amount of metals is predetermined tocorrespond to the maximum volume which will just fill the internal porevolume of the support, with no liquid in excess on impregnation of thesupport. Various refractory inorganic oxide supports are useful in theformaton of catalysts pursuant to the practice of this invention.Exemplary of such supports are titania, which is preferred, silica,silica-alumina, alumina, and the like.

Highly concentrated metal salt solutions are most desirable forpreparing hydrocarbon synthesis catalysts because they generate thehighest metal loading per impregnation, higher metal loadings leading inturn to higher catalytic activity. Common salts or compounds of thecatalytic metals can generally be used. However, it has been found thatthe nitrate salt, especially in the case of cobalt is preferred becauseit is the most readily available and least expensive salt and, moreimportantly, it possesses the highest degree of solubility in water.Cobalt acetate is also suitable, although it is less water soluble.Cobalt chloride and sulfate are not suitable for making hydrocarbonsynthesis catalysts, presumably because of poisoning by residual anionsnot removed in the calcination, regardless of the promotion ofdispersion by polyols. Solvents other than water may be used, e.g.,alcohols, ketones and the like, but these solvents are generally notpreferred because of lower metal salt solubility and added manufacturingcost. Suitable rhenium compounds are the common water soluble species,especially perrhenic acid and ammonium perrhenate.

The catalytic metal, copper or Iron Group metal, preferably the latter,and more preferably cobalt, is added to the support in amount sufficientto provide from about 2 percent to about 50 percent, preferably fromabout 5 percent to about 35 percent of the elemental metal, based on thetotal weight of the finished catalyst (wt. %: dry basis). The maximummetal loading that can be obtained per impregnation will depend upon thesupport pore volume, which will in turn depend upon the supportcomposition, and the metal concentration in the impregnating solution.Multiple impregnation/calcination steps may be used to obtain high finalmetal loadings. Other metals, e.g., thorium, cerium, hafnium, uraniumand the like can be added if desired to modify or promote the activityof the finished catalyst. These metals when present are added in weightratio to copper or Iron Group metal ranging above about 0.01:1,preferably from about 0.025:1 to about 0.1:1. Rhenium is added to thesupport in concentration sufficient to provide a weight ratio ofelemental rhenium:elemental copper or Iron Group metal (e.g., Re/Coweight ratio) in the finished catalyst ranging from about 0.005:1 toabout 0.2:1, preferably from about 0.01:1 to about 0.1:1 (dry basis).The polyol is added to the impregnating solution in concentrationranging from about 2 percent to about 20 percent, preferably from about6 percent to about 15 percent, based on the weight of the totalsolution; and the solution is contacted with the support to disperse themetal compound, or compounds, onto the support. In such treatment itdisperses the metal, or metals, onto the support even more effectivelythan the rhenium. The catalyst, after impregnation, is dried by heating,suitably at temperatures ranging from about 30° C. to about 120° C., inan air, nitrogen or other gas stream or under vacuum. The metals areconverted to an oxide form by calcination, suitably at temperatureranging from about 200° C. to about 550° C., preferably from about 250°C. to about 400° C., and the polyol is burned, combusted, and removedfrom the catalyst. The catalyst is then activated by reduction, suitablyby contact with hydrogen at temperature ranging from about 250° C. toabout 550° C., preferably from about 275° C. to about 425° C., forperiods ranging from about 0.5 hour to about 24 hours at pressuresranging from above ambient to about 40 atmospheres.

The catalyst produced in accordance with this invention, particularlythose comprised of the Iron Group metals, corresponds in composition tothose known, and useful in the conversion of synthesis gas to C₅+hydrocarbons. The Fischer-Tropsch, or hydrocarbon synthesis process iscarried out at temperatures of about 160° C. to about 325° C.,preferably from about 190° C. to about 260° C., pressures of about 5 atmto about 100 atm, preferably about 10-40 atm and gas hourly spacevelocities of from about 300 V/Hr/V to about 20,000 V/hr/V, preferablyfrom about 500 V/hr/V to about 15,000 V/hr/V. The stoichiometric ratioof hydrogen to carbon monoxide in the synthesis gas is about 2.1:1 forthe production of higher hydrocarbons. However, H₂/CO ratios of 1:1 toabout 4:1, preferably about 1.5:1 to about 2.5:1, more preferably about1.8:1 to about 2.2:1 can be employed. These reaction conditions are wellknown and a particular set of reaction conditions can be readilydetermined by those skilled in the art. The reaction may be carried outin virtually any type reactor, e.g., fixed bed, moving bed, fluidizedbed, slurry, bubbling bed, etc. The waxy, or paraffinic product from theF-T reactor, or reactor utilizing the catalyst made pursuant to thepractice of this invention is an essentially non-sulfur, non-nitrogen,non-aromatics containing hydrocarbon. It is a liquid which can beproduced and shipped from a remote area to a refinery site for furtherchemically reacting and upgrading to a variety of products, or producedand upgraded at a refinery site. Separator products from an F-T reactor,i.e., hot separator and cold separator liquids, respectively, i.e.,C₄-C₅ hydrocarbons, constitute high quality paraffin solvents which, ifdesired, can be hydrotreated to remove olefin impurities, or employedwithout hydrotreating to produce a wide variety of wax products. Thereactor wax, or C₁₆+ liquid hydrocarbons from the F-T reactor, on theother hand, can be upgraded by various hydroconversion reactions, e.g.,hydrocracking, hydroisomerization catalytic dewaxing, isodewaxing, etc.or combinations thereof, to produce such products as stable,environmentally benign, non-toxic mid-distillates, diesel and jet fuels,e.g., low freeze point jet fuel, high cetane jet fuel, etc.isoparaffinic solvents, lubricants, e.g., lube oil blending componentsand lube oil base stocks suitable for transportation vehicles, non-toxicdrilling oils suitable for use in drilling muds, technical and medicinalgrade white oil, chemical raw materials, and various specialty products.

The following non-limiting examples, and comparative demonstrations,exemplify the more salient and preferred embodiments of the invention.

EXAMPLES

A series of catalysts were prepared by impregnating a support, generallya rutile or anatase titania support, and silica, with a concentratedaqueous solution of cobalt nitrate and perrhenic acid via the incipientwetness technique. In most of the preparations, as tabulated hereafter,different polyols were dissolved in cobalt nitrate/perrhenic acidsolutions, the polyol generally being added in greater than 10 wt. %concentration in the impregnating solution. The amount of water presentin each impregnating solution was adjusted for the weight of the polyoladded to maintain a nearly constant 15 wt. % cobalt, calculated aselemental cobalt, in the solution. In base case preparations, forcomparative purposes, no polyol was added to the cobaltnitrate/perrbenic acid solution. In some cases the catalysts were madeby single impregnations (about 7 wt. % Co in the finished titaniasupported catalysts) in the exploration of preparation variables. Inother cases, a second impregnation was applied to increase metalsloadings and produce finished catalysts more typical of those which maybe employed in large scale operations. In each preparation, afterimpregnation the catalyst was dried and then calcined in air todecompose the nitrate salt to the oxide and burn off the organicadditive.

Most of the preps were made with a spray-dried titania support. Twobatches were used which were obtained by calcining the raw spray-driedsupport at two different temperatures, as indicated in the followingtable. A spray-dried silica support was also used in a few examples.

Calcination Surface Area H₂O Pore Designation Temp. °C. m²/g Volume,cc/g Rutile⁽¹⁾ 1000 19 0.33 Anatase⁽²⁾ 500 29 0.50 Silica 800 170 1.02⁽¹⁾94% Rutile - 6% Anatase TiO₂ ⁽²⁾27% Rutile - 73% Anatase TiO₂

The catalysts were characterized by the following tests.

O₂ Chemisorption: measured with O₂ pulses in helium at 25° C. afterreduction in hydrogen at 450° C. Results are expressed as micromoles O₂per gram and as an O/Co atomic ratio. The oxygen chemisorption is ameasure of the relative dispersion of cobalt oxide on the support.

Fixed Bed Hydrocarbon Synthesis (HCS) Test: conducted at 200° C., 280psig, with a syn gas feed of 64H₂-32CO-4Ne and space velocity adjustedas required to give conversion around 70% at 20 hours on stream.Catalysts were diluted with 1-7 parts by volume of titania to minimizetemperature gradients in a 0.25 inch ID reactor, used to conduct thetest. Prior to introducing the syn gas, the catalyst is reduced in situin hydrogen for one hour at 450° C. Conversion of CO and selectivity tomethane (mole % of CO converted to CH₄) are shown in Table 2. Values for“Cobalt Productivity,” which has the units of liters of CO converted perhour per gram of cobalt, are also included in Table 2.

Table 1: Effect of Polyols As Dispersion Aids

Table 1, Examples 2-5, summarizes the results obtained with differentpolyols as impregnation aids for dispersing cobalt throughout a support.Example 1 is a control; no polyol having been added to the impregnatingsolution. All of Examples 1-5 were made with the rutile titania support,without having added any rhenium promoter. The key results are given inthe second to last column, i.e., reference being made to the O/Cochemisorption data. The catalysts are grouped according to the length ofthe longest carbon chain in the polyol, or organic used as a dispersingaid. Example 1, as indicated, demonstrates for comparative purposes arun made without use of any polyol in the preparation. Example 2 showsno improvement when the catalysts are produced by dispersion of thecobalt with polyvinyl alcohol. In Examples 3-5, on the other hand,wherein glycerol and sorbitol, respectively, were used in thepreparations, higher relative dispersions were obtained. These alcoholsgive O/Co values ranging from 0.360 to 0.546 compared to values of lessthan 0.3 for the base case and the run made with the polyvinyl alcohol.From a list of the structures of the polyols tested, the criticalstructural features of the preferred polyols are shown to have a totalcarbon chain of at least 3 atoms, preferably 5 atoms. The polyols, it isbelieved, improve cobalt dispersion by covering the titania surface witha thin “blanket” of the polyol, which provides a trap for moltenanhydrous cobalt nitrate as it is generated in the pores during thedrying/calcination process. In the absence of something so polar to bindto, the cobalt salt probably coalesces into larger crystallites as itdecomposes to the oxide.

In Examples 6-14 both cobalt and rhenium were impregnated onto ananatase titania support. Example 6 is employed as a control. No polyolwas added to the solution in this run to impregnate the anatase titaniasupport. Examples 7-14, on the other hand, give the results obtainedwhen different hydroxyl-containing compounds, or polyols were added tothe impregnating solution to impregnate both cobalt and rhenium into theanatase titania support. In these runs, comparing the O/Co ratios ofExamples 6 and 7, it was found that the 1,2-hexanediol was ineffective;and although the O/Co ratio of the catalysts was improved with the useof the 1,6-hexanediol and 1,2,6-trihydroxyhexane, respectively, anexotherm developed when drying the catalysts that damaged the catalysts.It is believed that this reaction developed as the result of anoxidation reaction, and may be avoided by use of a water soluble cobaltcompound other than cobalt nitrate, e.g., cobalt acetate. On the otherhand, all O/Co values obtained in Examples 10-14, which used preferredpolyols as impregnation aids, were for the most part considerably higherthan in the base case.

Impregnation of a silica support with an impregnation solutioncontaining increasing concentrations of sorbitol as the dispersing aid,to disperse cobalt and rhenium onto the support (Examples 16-18)vis-a-vis the control which contained no dispersing aid (Example 15)likewise shows increasing O/Co ratios.

TABLE 1 Polyols As Dispersion Aids Wt % Polyol Example in impregPolyol/Co Wt % Wt % O₂ Exotherm (Cat. #) Support Organic soln* mol ratioCo Re Chemis O/Co in drying  1 Rutile TiO₂ None 0 0 7.06 0 165 0.276  2Rutile TiO₂ Polyvinyl Alcohol 1 — 6.78 0 154 0.268  3 Rutile TiO₂Glycerol 7.2 0.306 7.3 0 223 0.360  4 Rutile TiO₂ Glycerol 10.4 0.4447.3 0 261 0.422  5 Rutile TiO₂ Sorbitol 10.4 0.224 7.28 0 337 0.546  6Anatase TiO₂ none 0 0 10.2 0.433 391 0.452  7 Anatase TiO₂1,2-Hexanediol 11 0.368 7.45 0.351 236 0.374 Yes  8 Anatase TiO₂1,6-Hexanediol 11 0.368 9.69 0.437 574 0.699 Yes  9 Anatase TiO₂ 1,2,6-11 0.324 9.92 0.423 500 0.595 Yes Trihydroxyhexane 10 Anatase TiO₂Ethylene Glycol 11 0.7 9.72 0.458 569 0.691 11 Anatase TiO₂ Glycerol 110.472 10 0.467 631 0.745 12 Anatase TiO₂ Erythritol 11 0.356 10.3 0.477601 0.689 13 Anatase TiO₂ Arabitol 11 0.286 10.3 0.444 613 0.702 14Anatase TiO₂ Sorbitol 11 0.238 10.1 0.454 610 0.713 15 SiO₂ none 0 017.4 0.77 776 0.526 16 SiO₂ Sorbitol 6.5 0.14 18.1 0.8 940 0.613 17 SiO₂Sorbitol 11.5 0.247 18.1 0.8 1749  1.140 18 SiO₂ Sorbitol 15.6 0.33718.1 0.8 1452  0.947 *15 wt % Co in solution

Table 2: Hydrocarbon Synthesis Tests With Co—Re—SiO₂ Catalysts

The incorporation of some rhenium permits maximization of thehydrocarbon synthesis activity of the catalyst. The polyols functionwell in generating cobalt dispersion, but the activity of the catalystdoes not correspondingly increase until the cobalt oxide is reduced tothe active zero-valent state. Simply applying higher temperature in thereduction step does not improve the activity because the growth of atitania overlayer with titania, or sintering of the cobalt metal in thecase of silica, are processes that are favored by higher temperaturewhich counteract any positive gains in reduction.

A series of four runs were made with each of the catalysts produced inthe preparations described by reference to Examples 15-18; the catalystof Example 15 being that used for the run described in Example 19; thecatalyst of Example 16 being that used for the run described in Example20; the catalyst of Example 17 being that used for the run described inExample 21, etc. Example 19 is a control; no polyol having been used toimpregnate the rhenium and cobalt into the silica support. In each ofExamples 20-22 however sorbitol was used in the impregnating solution ingradually increased concentration. The Cobalt Productivity of thecatalysts, as will be observed, shows a rapid improvement, i.e., from2.66 (Example 19) to 3.55 (Example 20), and with the introduction ofsorbitol as a dispersing aid, up to 5.16 (Examples 21, 22).

While Cobalt Productivity is very useful in assessing cobalteffectiveness in the hydrocarbon conversion reaction, WeightProductivity is the activity measure that best defines the relativeperformance of a catalyst in a slurry reactor. Weight Productivityresults (cc CO converted per hour per gram of catalyst) for Examples19-22 show that the higher metal loading obtained with the silicasupport is significant.

TABLE 2 Hydrocarbon Synthesis Tests With Co-Re-SiO₂ Catalysts Example Wt% Wt % % org in Co Co Wt (Run #) Co Re Organic soln GHSV Conv Mol % CH₄Prod Prod Run Conditions: 200 C, 280 psig, 64% H₂-32% CO-4% Ne, 20 hrdata, 0.567 g/cc cat density, reduced in H₂ 450 C-1 hr. 19 17.4 0.77none 0 2000 41 7.4 2.66 463 20 18.1 0.8 Sorbitol 6.5 2000 57 6.5 3.55643 21 18.1 0.8 Sorbitol 11.5 2400 69 7 5.16 935 22 18.1 0.8 Sorbitol15.6 2400 69 7.3 5.16 935

Complete reduction of the catalytic metal, or metals, is required toachieve full catalyst activity. Full catalyst activity however can beachieved by only a small amount of rhenium, even at lower reductiontemperatures. Surprisingly, as little as {fraction (1/10)} of the basecase amount of rhenium will satisfactorily promote the reduction whenthe dispersion is accomplished by the presence of the polyol. Thecopresence of the polyol with the rhenium allows drastic reductions inthe amount of rhenium employed while yet achieving full dispersion andreduction of the catalyst.

Having described the invention, what is claimed is:
 1. A process for theproduction of C₅+ liquid hydrocarbons from a hydrogen and carbonmonoxide synthesis gas by contact of the synthesis gas at FischerTropsch reaction conditions with a catalyst prepared by impregnating arefractory in organic oxide support with a solution containing (a) acompound or salt, of a catalytic metal, and (b) a polyol having theformula CnH_(2n+2)O_(x); where n is an integer from 2 to 6, x is aninteger from 2 to 11, sufficient to disp the compound or salt onto thesupport, drying and removing the polyol, forming oxides of the metal onthe support, and activating the catalyst.
 2. The process of claim 1wherein the catalytic metal comprises cobalt.
 3. The process of claim 2wherein at least a portion of the C₅+ liquid hydrocarbon is subjected toconversion.
 4. The process of claim 3 wherein the conversion ishydroconversion.
 5. The process of claim 4 wherein the hydroconversionis hydroisomerization.
 6. The process of claim 5 wherein diesel fuelsare produced.
 7. The process of claim 5 wherein jet fuels are produced.8. The process of claim 5 wherein the hydroconversion is catalyticdewaxing.
 9. The process of claim 8 wherein lube oil base stocks areproduced.